your instincts are right: dont wean!! if you think about it, taking away something else your daughter loves and cherishes will only make the situation WORSE! this is horrid advice, and im speechless that someone would think that this was the best for your child. they have no right to say that! you have every right as her mother to be the one who decides how and when to nurse. NOT some child care provider.
contact a local or nearby la leche league group! www.llli.org will have a place where you can see all the groups in your state. look carefully, there might not be one in your town, but there might be one nearby you. its worth the search.
you remember; you are hiring the day care. not the other way around. you pay HER. so you are the one in control of the situation here. you have every right to remove her from that day care and find someone or another place that will be more kind and polite to you and find other ways than weaning to do this.
this is so so so common for kids this age to feel this way about separations. have you tried leaving something of yours with her? a shirt, a pillowcase, something that smells like you? does she have her own little blankie, a nuk, something she snuggles with? try sending something with her that might comfort her.
obviously, they are not doing a good job transitioning her. babies that age are usually easy to distract. have they tried playing with her, distracting her with something else, with other kids, with a movie? what have THEY done that makes your daughter hate to be there so badly that shes crying for hours? this doesnt sound right to me. as a former child care provider, i NEVER had a child cry longer than 30 minutes after drop off and even that long was rare. you can always distract them with a toy, a swing, a movie, a song, a game. i cant imagine your daughter being that upset for that long unless they are spending the whole time trying to get her to stop crying and forgetting about the fact that kids are easily distractable.
in other thoughts; is she getting enough sleep in general? its typical for kids this age to still need 2 naps a day. are they not considering that shes crying because she is tired and in need of her first nap? is she not sleeping well enough at home ?
im so so so sorry you have to go through this but im even more sorry that you are being "forced" to wean for some day care lady's selfish reasons. im sorry, but that is NOT right. it is NOT selfish of you to want to give your child the best that there possibly is for her!! your milk is not only perfect for her because its human milk for human babies, but its perfect for her exactly at the age she is!! milk changes over time, and even for kids over a year old, it provides a lot of immunity, not to mention the comfort aspect! :) :) just keep nursing mama!! you are doing the right thing! :)